OBJECTIVE: To determine if the cryopreservation of epididymal and testicular spermatozoa alters their reproductive potential by examination of patients who underwent consecutive cycles of ICSI using fresh and then cryopreserved spermatozoa. DESIGN: Retrospective review. SETTING: Tertiary care university hospital. PATIENT(S): One hundred sixty-two consecutive cycles of ICSI were analyzed. Thirteen patients were identified as having undergone treatment with freshly retrieved epididymal spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. Eighteen patients underwent ICSI with freshly retrieved testicular spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Fertilization rates and pregnancy rates. RESULT(S): The fertilizing capacity of epididymal spermatozoa remained unchanged after cryopreservation and subsequent thawing, with fertilization rates of 58% and 57% for fresh and cryopreserved spermatozoa, respectively. Testicular spermatozoa, however, showed a significant decrease in fertilizing capacity after cryopreservation when compared with freshly retrieved spermatozoa (52% and 71%, respectively). Pregnancy rates appeared unaffected by the cryopreservation of epididymal spermatozoa (fresh, 3/13; frozen, 2/13) or testicular spermatozoa (fresh, 2/18; frozen, 5/18). CONCLUSION(S): This study offers further evidence that motile epididymal spermatozoa retain their fertilizing capacity after cryopreservation. The data presented on testicular spermatozoa suggest that although cryopreservation may reduce the fertilizing capacity of testicular spermatozoa, there is no decrease in pregnancy rates.
OBJECTIVE: To determine if the cryopreservation of epididymal and testicular spermatozoa alters their reproductive potential by examination of patients who underwent consecutive cycles of ICSI using fresh and then cryopreserved spermatozoa. DESIGN: Retrospective review. SETTING: Tertiary care university hospital. PATIENT(S): One hundred sixty-two consecutive cycles of ICSI were analyzed. Thirteen patients were identified as having undergone treatment with freshly retrieved epididymal spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. Eighteen patients underwent ICSI with freshly retrieved testicular spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Fertilization rates and pregnancy rates. RESULT(S): The fertilizing capacity of epididymal spermatozoa remained unchanged after cryopreservation and subsequent thawing, with fertilization rates of 58% and 57% for fresh and cryopreserved spermatozoa, respectively. Testicular spermatozoa, however, showed a significant decrease in fertilizing capacity after cryopreservation when compared with freshly retrieved spermatozoa (52% and 71%, respectively). Pregnancy rates appeared unaffected by the cryopreservation of epididymal spermatozoa (fresh, 3/13; frozen, 2/13) or testicular spermatozoa (fresh, 2/18; frozen, 5/18). CONCLUSION(S): This study offers further evidence that motile epididymal spermatozoa retain their fertilizing capacity after cryopreservation. The data presented on testicular spermatozoa suggest that although cryopreservation may reduce the fertilizing capacity of testicular spermatozoa, there is no decrease in pregnancy rates.